In-vitro antibacterial screening of methanol extracts of three combretum species against seven strains of methicillin resistant staphylococcus aureus (MRSA)

Background: Medicinal plants are valued as sources of natural compounds some of which are effective against several infectious diseases. Plants from the genus Combretum have been used traditionally in various African societies to treat variety of medical problems especially infectious diseases.Objective: In this study, we investigated the antibacterial activity of the methanol extracts from the leaves of three Combretum species namely Combretum hispidum, Combretum racemosum and Combretum platypterum against seven strains of methicillin resistant Staphylococcus aureus (MRSA) in vitro.Materials and methods: Methanol extract from Combretum hispidum, Combretum racemosum and Combretum platypterum were subjected to agar diffusion assay and broth micro-dilution test for the determination of antibacterial activity and minimum inhibitory concentration (MIC), all the extracts were tested against eight different strain of MRSA. Imipenem and ciprofloxacin were used as control.Results: Extract from Combretum racemosum leaves showed significant anti-MRSA activity with zone of inhibition as high as 37 mm and MIC values ranging from 0.16 - 1.25 mg/mL on all tested strains of MRSA. Extracts from the two other species did not exhibit any activity on all tested strain.Conclusion: Methanol extract from C. racemosum is highly effective against MRSA and it could be a potential source of newer antimicrobial agent against MRSA infections

Cajachalcone: An Antimalarial Compound from Cajanus cajan Leaf Extract.

Cajanus cajan L, a member of the family Fabaceae, was identified from the Nigerian antimalarial ethnobotany as possessing antimalarial properties. The bioassay-guided fractionation of the crude methanol extract of C. cajan leaves was done in vitro using the multiresistant strain of Plasmodium falciparum (K1) in the parasite lactate dehydrogenase assay. Isolation of compound was achieved by a combination of chromatographic techniques, while the structure of the compound was elucidated by spectroscopy. This led to the identification of a cajachalcone, 2',6'-dihydroxy-4-methoxy chalcone, as the biologically active constituent from the ethyl acetate fraction. Cajachalcone had an IC50 value of 2.0 µ g/mL (7.4 µ M) and could be a lead for anti-malarial drug discovery.

Inhibitory activities of selected south west Nigerian medicinal plants against mycobacterium tuberculosis.

INTRODUCTION: Tuberculosis (TB), an infectious disease prevalent in the tropics especially in Africa and Asia is one of the highest causes of morbidity and mortality and a global concern. With increasing resistance of the pathogen, to existing antituberculosis drugs and the synergy between TB infection and acquired immune deficiency syndrome (AIDS), the need for development of new drugs to cope with the infection is urgent. OBJECTIVE: Extracts from 16 plants identified and selected from the ethnomedicine of the Ijebus in Southwestern Nigeria as remedies for tuberculosis were evaluated for activity against Mycobacterium tuberculosis, in vitro. METHODOLOGY: Plant extracts were screened against clinical isolate of Mycobacterium tuberculosis using agar plate method on Middlebrook 7H11 medium and observed for 12 weeks. RESULTS: The crude aqueous methanol extracts. showed varying degrees of activity at concentrations of 0.025 - 100 mg/mL. Ocimum grattisimum (leaf) demonstrated the highest activity with minimum inhibitory concentration (MIC) of 0.025 mg/mL. Two standard anti-tuberculosis drugs; rifampicin and isoniazid, included in the assay had MIC values of 0.01 mg/mL and 0.0005 mg/mL, respectively. CONCLUSION: The results of the study confirm the ethnopharmacological uses of some of the plants for TB indicating their potential as sources for the discovery of anti-tuberculosis drugs.

Anti-inflammatory and antimicrobial activities of Hippocratea indica root bark and Poga oleosa fruits.

The methanolic extracts of Hippocratea indica root bark and Poga oleosa fruits were investigated for anti-inflammatory and antimicrobial activities. Both extracts inhibited carrageenan-induced paw oedema significantly in rats in a dose-dependent manner in 4 h. H. indica inhibited oedema significantly at the minimal dose (125 mg/ml, p< 0.05) from 2 h onward, and gave 100% inhibition in 4 h. at 250 mg/kg. It was shown to be a more potent anti-inflammatory agent than P. oleosa. Also, H. indica extract exhibited greater antimicrobial activity against tested bacteria, with Staphylococcus aureus being the most susceptible bacterium (MIC, 16 mg/ml). Both plants were inactive against Candida albicans. These results confirm the anti-inflammatory and antibacterial activities of the two plants.

A phytotherapeutic approach to Nigerian anti-HIV and immunomodulatory drug discovery.

Effective therapies for management of HIV infection are top priority due to the high rate of morbidity and mortality of the disease, globally and this has assumed devastating dimension in the African continent. In Nigeria, many patients use herbal remedies for the management of HIV/AIDS, without sufficient scientific proof that they possess anti-HIV activity. In this report, the role of the tropical rainforest plants, identified through ethnomedical approach, as a source of antiviral and immunomodulating agents is highlighted. Some plant derived antiviral and immunomodulatory agents are briefly discussed. An outline of in vitro antiviral and immunomodulatory assays that can be adapted to the Nigerian environment is given. The urgent need to identify and evaluate the medicinal plants in the Nigerian biodiversity reputedly used for management of viral infections is also emphasized.